Suture buttress

ABSTRACT

A suture buttress includes a hollow tube having an outer surface and opposed ends. The suture buttress may further include an external securing element, such as a securing tab suitable to retain the suture buttress within a bone tunnel. The suture buttress may also include a resilient flange disposed on one end of the suture buttress.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of Application No.09/004,989, filed Jan. 9, 1998, titled “SUTURE BUTTRESS SYSTEM”.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not Applicable.

FIELD OF THE INVENTION

The invention relates to a suture buttress, and more particularly to asuture buttress having a securing element which retains the suturebuttress within a bone tunnel.

BACKGROUND OF THE INVENTION

Open repair of the rotator cuff tendon is the most common open surgicalprocedure performed on the shoulder. It has been estimated that theincidence of rotator cuff tearing in the population at large runsbetween 15 and 25%, with approximately half of these being fullthickness tears of the tendon. A smaller percentage of these becomesufficiently symptomatic to warrant surgical repair.

Generally, techniques for repairing rotator cuff tears involvereattaching the torn tendon back to the bone from which it is avulsed.Typically, suture material is used to tie the tendon directly back tobone to facilitate healing of the tendon. Common technical problems withthis repair often result from the fact that rotator cuff tearsfrequently occur in patients who are in an older age group. Thesepatients often have poor quality bone, osteopenic bone, or bone that hasbeen weakened by disuse due to pain. When the tendon is brought back tothe bone, attempts to hold the tendon securely to the bone can befrustrated by the poor quality bone.

One method for reattaching the rotator cuff tendon to bone is to make ahole or tunnel in the bone of the greater tuberosity, to pass suturethread that has been secured to the tendon through these bone tunnels,and to reattach the rotator cuff tendon directly to the bone by tyingthese sutures. Using this method, the suture material can be frayed andweakened, or possibly severed, by contact with sharp edges ofsubcortical bone inside the bone tunnel or at the openings of the bonetunnel.

Poor bone quality also affects this method of repair adversely as thesuture material may cut directly through the bone, frustrating theattempts at secure repair. Even where the suture does not cut completelythrough the bone, any amount of carving into bone by the suture materialmay result in a loosening of the suture and a corresponding loosening ofthe attachment of the rotator cuff tendon to bone.

SUMMARY OF THE INVENTION

The present invention provides a suture buttress having a hollow tubeincluding an external securing element made up of at least one tabdisposed on an outer surface of the suture buttress. The tabs are formedat an angle to a longitudinal axis of the suture buttress so that thetabs extend outward from the outer surface of the suture buttress. Thetabs are resiliently deformable and may be recessable within cut-outsformed in the outer surface of the suture buttress, allowing the tabs todeform as the suture buttress slides into a bone tunnel in a firstdirection when inserted into a bone tunnel. After insertion of thesuture buttress in the bone tunnel, the tabs engage the tunnel toprevent the suture buttress from sliding out of the tunnel. In oneembodiment, a resilient flange is also disposed on the outer surface ofthe buttress. The resilient tube may also be constructed of a porousmaterial or have pores formed thereon to promote bone ingrowth in a bonetunnel.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood by reference to thefollowing detailed description when considered in conjunction with theaccompanying drawings, in which:

FIG. 1 is an elevated view of a suture buttress system showing a distalportion of a suture retriever, a suture buttress disposed on theretriever and a suture retaining element extending from the retriever;

FIG. 2 is an elevated view of the suture buttress of FIG. 1 in anunflexed position;

FIG. 3 is an elevated view of the suture buttress of FIG. 1 in a flexedposition;

FIG. 4 is a cross-sectional view of a suture buttress having flanges;

FIG. 5 is a cross-sectional view of a suture buttress having opposedends folded over onto an outer surface of the buttress; and

FIG. 6 is an elevated view of a suture buttress system including asuture buttress deployment tool;

FIG. 7 is an elevated view, with a partial cut-away, of the sutureretriever of FIG. 1, with the suture retaining element in a retractedposition;

FIG. 8 is an elevated view, with a partial cut-away, of the sutureretriever of FIG. 1, with the suture retaining element in an extendedposition;

FIG. 9 is an elevated view, with a partial cut-away, of the sutureretriever of FIG. 1, with the suture retaining element in a partiallyretracted, intermediate position;

FIG. 10 is an elevated view of the suture retaining element of FIG. 1 inan extended position;

FIG. 11 is an elevated view, with a partial cut-away, of the sutureretaining element of FIG. 1 in an intermediate position;

FIG. 12 is an elevated view of a suture tunnel buttress system having aninternal tube delivery scheme;

FIG. 13 is a perspective view of an additional suture buttress inaccordance with the teachings of the present invention;

FIG. 14 is a right side view of the suture buttress of FIG. 13;

FIG. 15 is a cross sectional view of the suture buttress taken alongline 15—15 in FIG. 14;

FIG. 16 is a bottom view of the suture buttress of FIG. 13;

FIG. 17 is a detailed view of portion A of the suture buttress of FIG.13;

FIG. 18 is a rear view of the suture buttress of FIG. 13;

FIG. 19 is a side view of the suture buttress of FIG. 13 in a flexedposition;

FIG. 20 is a side view of the suture buttress of FIG. 13 in conjunctionwith a suture retriever;

FIG. 21 is a perspective view of a suture buttress bone rasp tool; and

FIG. 22 is a top view of the bone rasp tool of FIG. 21.

DETAILED DESCRIPTION OF THE INVENTION

An exemplary suture buttress system 10 of the invention, illustrated inFIG. 1, includes a suture retriever 12 and a suture buttress or bonetunnel buttress 14. The suture retriever 12 has an elongate portion 16having an outer surface 18 and a suture retrieving element 20 disposedat its distal end 22. The suture buttress 14 is removably andreplaceably disposed on the outer surface 18 of the elongate member 16.A suture buttress stop 24 may also be provided on the outer surface 18of the elongate member 16 in proximity to the suture buttress 14.

The suture buttress 14, illustrated in FIGS. 1-3, includes a resilienthollow tube 26 having an outer surface 28 and opposed proximal anddistal ends 30, 32. The resilient hollow tube 26 may be made from avariety of resilient materials including absorbable and non-absorbablematerials. Exemplary non-absorbable polymeric materials includepolysulfone, PEEK, Nylon and Delrin. Exemplary bioabsorbable materialsuseful for making the resilient hollow tube 26 include homo andcopolymers of glycolide and trimethylene carbonate, homo and copolymersof lactide and glycolide, homo and copolymers of polylactic acid, or acombination of these materials. Additionally, the resilient hollow tube26 may be constructed from the same materials used to construct suturesfor use in orthopedic procedures, including polydioxanone (PDS) andother materials known to those of ordinary skill in the art.

The resilient tube 26 should have sufficient length 34 to protect asuture as applied in surgical procedure and, in particular, in anorthopedic procedure where the suture is passed through a bone tunnel.Generally, where the suture buttress system 10 is used in rotator cuffrepair surgery in which a suture is passed though a bone tunnel in theproximal humerus, the length 34 of the resilient tube should be betweenabout 0.75 and 1.50 inches.

The inner diameter 36 of the resilient tube 26 should be large enough toallow the tube 26 to be removably and replaceably disposed on the outersurface 18 of the suture retriever 12 and large enough to allow a sutureto be drawn through the tube 26. In addition, the inner diameter 36 mustbe selected so that, with an appropriate wall thickness 38, theresilient tube 26 will fit within a suitably sized bone tunnel.Generally, for use in rotator cuff repair surgery, the inner diameter 36of the resilient tube 26 is between about 0.060 and 0.085 inch and thewall thickness 38 is between about 0.014 and 0.018 inch.

The resilient tube 26 may be provided with an external fastening elementthat is effective to secure it within a bone tunnel. The exemplaryresilient tube 26 is provided with at least one angled slit 40 for thispurpose. Each slit 40 is angled by an amount with respect to a plane 42that is transverse to a longitudinal axis 44 of the resilient tube 26.While the angle α may take on any value, α is preferably positive andmore preferably is between about 20° and 60°. When the slits 40 are soangled, flexing the resilient tube (as shown in FIGS. 1 and 3) causes aseries of raised edges 46 to extend outward from the outer surface 28 ofthe resilient tube 26. The edges 46 are angled so that they are easilydeformed and pressed back to the outer surface 28 to allow the resilienttube 26 to slide into a bone tunnel when urged in a first direction 46into the bone tunnel by a surgeon when inserting the suture retriever 12into the tunnel.

The suture buttress stop 24, provided on the outer surface 18 of theelongate member 16 in proximity to the suture buttress 14, may preventthe resilient tube 26 from sliding backwards on the outer surface 18 ofthe elongate member 16 during insertion of the suture retriever 12 intoa bone tunnel in the first direction 46. The suture buttress stop 24 maybe formed by cutting out or otherwise deforming a portion of the outersurface 18 of the elongate member 16, by attachment to the outer surface18, or in some other manner that may be selected by a person of ordinaryskill in the art.

Once the resilient tube 26 has been inserted into a bone tunnel, theraised edges 46 engage the inner surface of the bone tunnel to preventthe resilient tube 26 from sliding out of the bone tunnel in a seconddirection 48, substantially opposed to the first direction 46, when thesuture retriever 12 is removed from the bone tunnel. The suture buttress14 is thus left in position within the bone tunnel as the sutureretriever 12 is used to draw a suture through the suture buttress 14 andthrough the bone tunnel.

The slits 40 should be deep enough to cause the desired raised edges 46when the resilient tube 26 is flexed, but not so deep as to compromisethe structural integrity of the resilient tube 26. Otherwise, the depthof the slits 40 is not particularly limited and the slits 40 may have adepth that is less than the wall thickness 38 of the resilient tube 26,or the slits 40 may be deeper than the wall thickness 38 so that theslits 40 extend into the interior of the tube 26.

One of ordinary skill in the art will appreciate that a variety of otherexternal fastening elements may be utilized to secure the suturebuttress within a bone tunnel. Examples of suture buttresses havingother external fastening elements are illustrated in FIGS. 4 and 5.Suture buttress 50 of FIG. 4 has a resilient hollow tube 51 with tworesilient circumferential flanges 52, 54 formed on the outer surface 56of resilient tube 51. One flange is formed adjacent to each of theopposed ends 58, 60 of the resilient tube 51. A person of ordinary skillin the art will appreciate that more or fewer flanges may be used andthat the location of the flanges may be varied as necessary to achievethe purpose of the invention. The suture buttress 62, illustrated inFIG. 5, includes portions of the resilient hollow tube 63 adjacent toeach of the opposed ends 64, 66 that are folded over onto outer surface68 of the tube 63. The suture buttresses 50, 62 of FIGS. 4 and 5 may beapplied using the suture retriever 12 illustrated in FIG. 1.

An additional suture buttress 200 of the invention is illustrated inFIG. 13. The suture buttress 200 includes a hollow tube 220, acircumferential flange 230, and an external securing element 240. Thetube 220 has an outer surface 222 and opposed proximal and distal ends224, 226.

The tube 220 further includes an inner lumen or passageway 232. In theembodiment of FIGS. 13-16, the inner lumen 232 may be tapered from thedistal end 226 to the proximal end 224. The inner lumen 232 has a firstdiameter 236 at the distal end 226 and a second diameter 238 at theproximal end 224. The inner lumen 232 at its smallest diameter should belarge enough to allow the tube 220 to be removably and replaceablydisposed on a suture retriever 260 as shown in FIG. 20, and large enoughto allow a suture to be drawn through the tube 220. In addition, thediameters must be selected so that, with an appropriate wall thickness239, the tube 220 will fit within a suitably sized bone tunnel.

Generally, for use in rotator cuff repair surgery, the first diameter236 at the distal end is between 0.070 and 0.100 inch and the seconddiameter 238 of the tube 220 at the proximal end is between about 0.060and 0.085 inch. The wall thickness 239 is between about 0.010 and 0.040inch. The tube 220 also has a constant outer diameter 237 in the rangeof about 0.1 to 0.2 inch.

Referring to FIGS. 13-20, the suture buttress 200 may be provided withan external securing element or tab 240 that is effective to secure itwithin a bone tunnel.

The exemplary suture buttress 200 is provided with at least one tab 240disposed in proximity to the proximal end 224, along the outer surface222 of the tube 220 for this purpose. Although the exemplary embodimentis shown with three tabs, less than three or more than three tabs my beused to secure the buttress within the bone tunnel. The at least one tab240 projects outward from the outer surface 222 of the tube 220, at anangle generally transverse to a longitudinal axis 244 of the tube 220.While the at least one tab 240 may project outward from the outersurface at any angle that is suitable to allow the tabs 240 to fold downupon insertion of the suture buttress within a bone tunnel, the tabs 240will generally extend outward at an angle of about 90°. In thisposition, tabs 240 can penetrate or extend into the surface of the bonetunnel when deployed to securely fasten the suture buttress 200 therein.

As shown in FIG. 17, the tube 220 may include thin slits 252 formed inthe outer surface 222 of the tube 220 adjacent to both sides (one shown)of the base of each tab 240 so that the tabs are easily deformed andflexed. Typically, the tabs 240 will be pressed back and recessed intocut-outs 228, positioned to provide clearance for the tabs 240 todeform, to allow the tube 220 to slide into a bone tunnel when urged ina first direction 301 into a bone tunnel by a surgeon, as discussed inmore detail later herein. The slits 252 should be deep enough to allowthe tab to bend and deform without detaching from the tube 220, but notso deep as to compromise the structural integrity of the tube 220.Otherwise, the depth of the slits 252 is not particularly limited andthe slits 252 may have a depth that is less than the wall thickness 239of the tube 220, or the slits 252 may be deeper than the wall thickness239 so that the slits 252 extend into the interior of the tube 220.Generally, the slits 252 may be thin, having a thickness of about 0.005to 0.010 inch.

Tab 240 may be formed by cutting out or otherwise deforming a portion ofthe outer surface 222 of the tube 220, by attachment of a separate tabpiece to the outer surface 222, injection molded in place, or in someother manner that may be selected by a person of ordinary skill in theart. In an exemplary embodiment, each tab has a width 246 of about 0.02to 0.04 inch, a thickness 248 of 0.02 inch to 0.03 inch and a height 250of about 0.03 to 0.05 inch. The tabs may be constructed of the samematerials as recited above for construction of the tube 220, such asPDS.

The suture buttress 200 of the present invention may also have aresilient circumferential flange 230 formed on the outer surface 222 oftube 220 to further secure the suture buttress 200 within the bonetunnel, i.e. to prevent the suture buttress 200 from sliding further ina first direction 301 into the bone tunnel, and to provide extrastrength at the lateral edge of the buttress 200. In the illustratedembodiment, the flange 230 is formed adjacent to the proximal end 224 ofthe tube 220, proximate to the at least one tab 240. A person ofordinary skill in the art will appreciate that more than one or even noflanges may be used and that the location of the flange(s) may be variedas necessary to achieve the purpose of the invention.

The flange 230 may be constructed of the same materials as recited abovefor construction of the tube 220, such as PDS. The flange 230 is angledby an amount δ with respect to a plane 232 that is transverse to alongitudinal axis 244 of the tube 220. While the angle δ may take on anyvalue suitable to retain the suture buttress 10 within the bone tunnel,δ is preferably between about 0° and 45° and more preferably about 15°.In an exemplary embodiment, the angle displacement δ of the flange 230is equal to the angular displacement θ of the tabs 240 with respect to aplane 242 that is transverse to a longitudinal axis of tube 220. Whilethe angle θ may take on any value suitable to retain the suture buttress10 within the bone tunnel, θ is preferably also between about 0° and 45°.

Generally, the suture buttress 200 as described herein is designed foruse with a suture retriever 260, as shown in FIG. 20. The sutureretriever 260 has an elongate member 262 having an outer surface 264 anda suture retrieving element 266 disposed at its distal end 268. Thesuture buttress 200 is removable and replaceably disposed on the outersurface 264 of the elongate member 262. As shown in FIG. 19 and 20, thesuture buttress 200 may be preformed in a curved shape to conform to theshape of the elongate member 262 of the suture retriever 260. In anexemplary embodiment, the suture buttress has a radius of curvature inthe range of about 0.300 to 0.600 inch and preferably, 0.434 inch.

In a further embodiment of the present invention, the suture buttresshas pores formed on the outer surface thereof which may extend throughthe walls of the buttress.

Alternatively, the suture buttress of the invention may be constructedof a porous material to facilitate and promote bone ingrowth. The boneingrowth further secures the suture buttress within the bone tunnel bybonding with the pores on the outer surface. In an exemplary embodiment,the pores have a diameter of about 100 to 500 microns. The pores wouldcover at least a portion of the suture buttress, preferably up to about50% of the total surface area of the tube. Such pores can be formedintegrally during the injection molding process or using a secondaryprocess, such as laser or mechanical drilling, after the buttress hasbeen formed.

A suture buttress system 70 may also include a suture buttressdeployment tool 72 as illustrated in FIG. 6. The suture buttressdeployment tool 72 has a handle 74 and a deployment element 76. Thedeployment element 76 may be removably and replaceably disposed on anouter surface 78 of the suture retriever 79 adjacent and proximal to asuture buttress 80. Because the suture buttress 80 can be deployed fromthe suture retriever using the deployment tool 72, the suture buttress80 need not have an external fastening element. Also, because thedeployment tool 72 may be used to urge the suture buttress 80 into abone tunnel, it is not necessary to provide a suture buttress stop, suchas the suture buttress stop 24 shown in FIG. 1, on the suture retriever79.

The deployment element 76 of the suture buttress deployment tool 72 maybe in the form of a partial or complete loop. In an embodiment in whichthe deployment element 76 is in the form of complete loop, the loop maybe circular. Such a circular loop has an inner diameter large enough toslide over the outer surface 78 of the suture retriever 79. However, theinner diameter of the circular loop should be less than the outerdiameter of the suture buttress 80 so that the circular loop can be usedto push the suture buttress 80 off of the outer surface 78 of sutureretriever 79.

The suture retrieving device 12 useful with the invention for retrievingor retrograding a suture or other ligature, is illustrated in FIGS.7-11. This exemplary instrument includes a handle 82, an elongate member16, a suture retaining element 20, an actuator 84 and a linking member86 which connects the actuator 84 to the suture retaining element 20.

The exemplary handle 82 is elongate, generally cylindrical and hasopposed proximal 88 and distal 90 ends. The shape and dimensions of thehandle 82 may be selected by a person of ordinary skill in the art toallow the handle 82 to be suitably grasped by a surgeon in an operatingenvironment.

The actuator 84 is slidably mounted on a side wall 92 of the handle 82.In the embodiment shown, the actuator 84 is rectangularly-shaped andincludes a series of flanges 94 having varying heights and angledsurfaces so as to be easily manipulated in either of two directions by asurgeon's thumb. The actuator 84 is mounted so as to slide in adirection substantially parallel to a longitudinal axis 96 of the sutureretriever 12 and is movable between a first position (shown in FIG. 7),wherein the actuator 84 is closest to the proximal end 88 of the handle82, and a second position (shown in FIG. 8), wherein the actuator 84 isclosest to the distal end 90 of the handle 82. The actuator 84 may alsobe selectively positionable at an intermediate location between thefirst and second positions as illustrated in FIG. 9.

The actuator 84 communicates with the interior of the handle 82 througha transverse member 98. The transverse member 98 may extend through arectangular slot (not shown) in the side wall 92 of the handle 82 alongwhich the actuator 84 slides.

The transverse member 98 of the actuator 84 is connected to the linkingmember 86, which may be a rigid or semi-rigid rod. Preferably, thelinking member 86 extends from the transverse member 98 in the interiorof the handle 82 through the interior of the elongate member 16 tocommunicate with the suture retaining element 20.

Detents may be provided to lock the suture retriever 12 in the fullyretracted and intermediate positions. These detents may suitably beprovided by forming protuberances 100, 102 on the interior of the handle82 corresponding to the fully retracted and intermediate positionsrespectively. A biased member 104 attached to the transverse member 98of the actuator 84 has a recess 106 which corresponds to the shape ofthe protuberances 100, 102. Accordingly, when the actuator 84 passesinto the first or intermediate position, a detent is achieved.

The distal end 22 of the elongate member 16 may extend at various anglesand with various curvatures. For example, the distal end 22 of theelongate member 16 is curved and sweeps though an arc of approximately180°. The suture retaining element 20 extends at an angle β, that isapproximately 135° with respect to the longitudinal axis 96 of thesuture retriever 12. The distal end 22 of the elongate member 16 mayalso take on other configurations which may be selected by a person ofordinary skill in the art for the intended use of the suture retriever12.

The suture retaining element 20 may be made from any flexible materialsuitable for surgical use including metals such as stainless steel orsuper elastic nickel-titanium (NITINOL), or plastic materials havingelastic properties such as polyester, polypropylene or nylon. The sutureretaining element 20 may be formed into a wire loop from a single,continuous wire element, or it may be formed using two wire elementsjoined at a distal portion of each.

The suture retaining element 20, illustrated in its extended position inFIG. 8, has two leg segments 108, 110. Beginning at a proximal end 112of the suture retaining element 20 and moving distally, the leg segments108, 110 diverge from one another, reach a point of maximum widththerebetween, then converge to meet at a distal end 114 of the sutureretaining element 20. The suture retaining element 20 thereby takes on aquadrangular or diamond shape when extended. In its extended position,the suture retaining element 20 has a maximum width between the legsegments 108, 110 in the range of approximately 0.100 to 0.800 inch, andmore preferably about 0.400 inch.

The suture retaining element 20 may also be retracted to an intermediateposition as shown in FIG. 11. As the actuator 84 is moved from itssecond or distal-most position to the intermediate position, thediverging portions of the two leg segments 108, 110 contact the innerwall 116 of the distal end 22 of the elongate member 16. This causes thequadrangular shaped wire loop suture retaining member 20 to compress, orfold up, as it is retracted into the elongate member 16. When theactuator 84 reaches the intermediate position, a small portion of thesuture retaining element 20 remains extended beyond the distal end 11 ofthe elongate member 16 and thereby defines a region 118 within thesuture retaining member 20 where a suture may be retained. The retainedsuture may then be drawn through a suture buttress 14 by the sutureretriever 12. In this partially retracted position, the width of thesuture retaining element 20 should be sufficient to slidably retain asuture within the suture retaining element 20. This width is generallyin the range of about 0.020 to 0.250 inch, and more preferably isapproximately 0.0675 inch. In this position, the suture retainingelement may generally extend approximately 0.0675 to 0.250 inch, andmore preferably extends about 0.125 inch from the distal end 22 of theelongate member 16.

Moving the actuator 84 to its first, proximal-most position fullyretracts the suture retaining element 20 within the distal end 22 of theelongate member 16 as shown in FIG. 7.

The suture retaining device of the invention may utilize other sutureretaining element configurations, such as a two-jaw suture retainingelement or a suture retaining element consisting of two wire-likemembers. Examples of suture retaining elements known in the art may befound, for example, in U.S. Pat. Nos. 4,779,616; 5,250,054; 5,364,410;5,499,991; 5,501,692; 5,562,685; 5,569,269 and 5,573,542.

An additional suture buttress system 120 having an internal tubedelivery scheme is illustrated in FIG. 12. The suture buttress system120 includes a suture buttress 122 that is at least partially disposedinside the distal end 123 of the elongate member of a suture retriever.In this embodiment, the leg portions 108, 110 extend proximally throughthe suture buttress 122 and form buttress deployment elements 124, 126which push the suture buttress 122 out from its position inside thedistal portion 123 and into a bone tunnel. External fastening elements,as described above, may be provided on the suture buttress 122 to retainit within the bone tunnel.

The suture buttress system may be employed in a variety of surgicalapplications, particularly those using a bone tunnel to attach softtissue to a bone using one or more sutures. An exemplary procedure forusing the suture buttress system with a bone tunnel begins with the stepof preparing the soft tissue to be attached to the bone by resectingdamaged portions and attaching at least one suture thread to the tissue.

A bone tunnel is then formed in proximity to the anatomic attachmentpoint of the soft tissue to the bone. The tunnel is formed by piercingthe cortical bone tissue at each end of the tunnel using a device suchas a cortical bone punch or a drill.

Referring to FIGS. 21 and 22, a circular bone rasp 290 may be used tocomplete the tunnel through subcortical bone. The rasp 290 is elongateand has opposed proximal ends 298 and distal ends 300. The rasp 290 mayhave a handle portion proximate the proximal end 298 and a cuttingportion 310 proximate the distal end 300. The cutting portion 310 mayhave teeth on its inner surface and/or outer surfaces which can be usedto smooth the subcortical bone and sharp cortical bone edges.Preferably, the cutting portion 310 has a radius of curvature to matchthe radius of curvature of the suture buttress, as described earlierherein. In addition, the cutting portion 310 may have a circular crosssection having same diameter as the suture buttress, ensuring a closefit of the buttress in the bone tunnel formed with bone rasp 290. Theshape and dimensions of the handle portion 294 may be selected by aperson of ordinary skill in the art to allow the handle 294 to besuitably grasped by a surgeon in an operating environment.

A suture buttress system, such as suture buttress system 10 illustratedin FIG. 1, is inserted, distal end 22 first and with the sutureretaining element 20 retracted, into the end of the bone tunnel oppositethe soft tissue. The suture buttress system 10 is inserted the suturebuttress 14 is fully disposed within the bone tunnel and the distal end22 of the suture retriever 16 reaches the opposite end of the tunnel.The suture retaining element 20 is used to grasp a suture by extendingthe suture retaining element 20 and directing the suture therethrough.The suture retaining element 20 is then retracted to its intermediate orretracted position as appropriate to slidingly engage or snugly engagethe suture. The suture retriever 16 is then removed from the bone tunnelso as to draw the suture through the tunnel and the suture buttress 14while leaving the suture buttress 14 in place within the tunnel. Thesuture is then secured in any manner known to one of ordinary skill inthe art in order to secure the soft tissue to the bone.

Where the suture buttress 200 (shown in FIGS. 13-20) is employed, thesuture buttress 200 is inserted until the suture buttress 200 is fullydisposed within the bone tunnel and the distal end 226 of the sutureretriever 260 reaches the opposite end of the tunnel. During insertionof the suture buttress 200, the tabs 240 recess into cut-outs 228 on theouter surface 222 of the tube 220. The suture retrieving element 266 isthen used to grasp a suture by extending the suture retrieving element266 and directing the suture, not shown, therethrough. The sutureretrieving element 266 is then retracted as appropriate to slidinglyengage or snugly engage the suture. The suture retriever 260 is thenremoved from the bone tunnel so as to draw the suture through the tunneland the suture buttress 200 while leaving the suture buttress 200 inplace within the tunnel. The suture is then secured in any manner knownto one of ordinary skill in the art in order to secure the soft tissueto the bone.

Once the suture buttress 200 has been inserted into a bone tunnel, thetabs 240, previously recessed in cut-out 228, spring outward to engageor penetrate into the inner surface of the bone tunnel, which typicallyincludes low density trabecular bone and soft marrow. The raised tabs240 thereby prevent the suture buttress 200 from sliding out of the bonetunnel in a second direction 302, substantially opposed to the firstdirection 301, when the suture retriever 260 is removed from the bonetunnel. The suture buttress 200 is thus left in position within the bonetunnel as the suture retriever 260 is used to draw a suture through thesuture buttress 200 and through the bone tunnel.

When a suture buttress of the invention is inserted into a curved bonetunnel, such as a bone tunnel produced by rasp 290, the buttresspreferably extends substantially through the tunnel to prevent a suturefrom damaging the inner walls of the curved portion of the tunnel.

The procedure as described above is particularly useful reattaching aninjured rotator cuff tendon to the proximal humerus, however, a personof ordinary skill in the art will be able to apply the system, buttressand procedure of the invention in a variety of surgical situations.

It will be understood that the foregoing is only illustrative of theprinciples of the invention, and that various modifications can be madeby those skilled in the art without departing form the scope and spiritof the invention. All references cited herein are expressly incorporatedby reference in their entirety.

What is claimed is:
 1. A suture buttress, comprising: a hollow tubehaving an outer surface and opposed ends; an external securing elementextending from the outer surface of the tube, the external securingelement including at least one tab disposed at an angle to alongitudinal axis of the tube, and wherein the at least one tab isresiliently deformable to allow the suture buttress to slide into a bonetunnel in a first direction when inserted into the bone tunnel, whileengaging the bone tunnel to secure the suture buttress within the tunnelafter insertion; and at least one cut-out portion formed on the outersurface of the tube, the cut-out portion positioned to receive the atleast one tab when the suture buttress is inserted into the tunnel in afirst direction.
 2. The suture buttress of claim 1, further comprisingat least one slit formed in the outer surface of the tube proximate theat least one tab, the at least one slit allowing the tab to flexrelative to the longitudinal axis of the tube.
 3. A suture buttress,comprising: hollow tube having an outer surface and opposed ends, anexternal securing element extending from the outer surface of the tube,the external securing element including at least one tab disposed at anangle to a longitudinal axis of the tube, and wherein the at least onetab is resiliently deformable to allow the suture buttress to slide intoa bone tunnel in a first direction when inserted into the bone tunnel,while engaging the bone tunnel to secure the suture buttress within thetunnel after insertion; and at least one resilient flange located on theouter surface of the suture buttress wherein the flange is positioned onthe opposed end proximate the at least one tab.
 4. A suture buttress,comprising: a hollow tube having an outer surface and opposed ends; andan external securing element extending from the outer surface of thetube, the external securing element including at least one tab disposedat an angle to a longitudinal axis of the tube; wherein the at least onetab is resiliently deformable to allow the suture buttress to slide intoa bone tunnel in a first direction when inserted into the bone tunnel,while engaging the bone tunnel to secure the suture buttress within thetunnel after insertion; and wherein the tube is constructed from anabsorbable material.
 5. A suture buttress, comprising: a hollow tubehaving an outer surface and opposed ends; and an external securingelement extending from the outer surface of the tube, the externalsecuring element including at least one tab disposed at an angle to alongitudinal axis of the tube; wherein the at least one tab isresiliently deformable to allow the suture buttress to slide into a bonetunnel in a first direction when inserted into the bone tunnel, whileengaging the bone tunnel to secure the suture buttress within the tunnelafter insertion; and wherein the tube includes a tapered inner lumenextending from a proximal to a distal end of the tube.
 6. The suturebuttress of claim 5, wherein the tube has a first inner diameter at thedistal end of about 0.070 to 0.100 inch and a second inner diameter atthe proximal end of about 0.060 to 0.085 inch.
 7. A suture buttress,comprising: a hollow tube having an outer surface and opposed ends; andan external securing element extending from the outer surface of thetube, the external securing element including at least one tab disposedat an angle to a longitudinal axis of the tube; wherein the at least onetab is resiliently deformable to allow the suture buttress to slide intoa bone tunnel in a first direction when inserted into the bone tunnel,while engaging the bone tunnel to secure the suture buttress within thetunnel after insertion; wherein a plurality of pores are formed in theouter surface of the tube to promote bone ingrowth from the bone tunnelinto the pores to further secure the suture buttress within the bonetunnel; and wherein the pores have a diameter of about 100 to 500microns.
 8. A suture buttress, comprising: a hollow tube having an outersurface and opposed ends; and an external securing element extendingfrom the outer surface of the tube, the external securing elementincluding at least one tab disposed at an angle to a longitudinal axisof the tube; wherein the at least one tab is resiliently deformable toallow the suture buttress to slide into a bone tunnel in a firstdirection when inserted into the bone tunnel, while engaging the bonetunnel to secure the suture buttress within the tunnel after insertion;wherein the tube is dimensioned to extend substantially through the bonetunnel; and wherein the tube has a length of about 0.75 to 1.50 inches.9. A suture buttress, comprising: a hollow tube having an outer surfaceand opposed ends; and an external securing element extending from theouter surface of the tube, the external securing element including atleast one tab disposed at an angle to a longitudinal axis of the tube;wherein the at least one tab is resiliently deformable to allow thesuture buttress to slide into a bone tunnel in a first direction wheninserted into the bone tunnel, while enraging the bone tunnel to securethe suture buttress within the tunnel after insertion; and wherein thetube is preformed in a curved shape.
 10. A bone tunnel buttress, systemcomprising: a bioimplantable elongate hollow tube having an outersurface and opposed proximal and distal ends, the hollow tube havingbone ingrowth pores formed on the outer surface thereof; at least oneexternal securing member formed on the outer surface of the tube, thebone tunnel buttress being effective for deployment within a bone tunnelsuch that the external securing member in cooperation with the outersurface pores, secures the buttress against removal from the bonetunnel, the external securing member comprising at least one resilientlydeformable tab disposed on the outer surface of the tube, the at leastone tab being formed at an angle to a longitudinal axis of the tube andextending outward from the outer surface of the bone tunnel buttress;and at least one cut-out portion formed on the outer surface of thetube, the cut-out portion positioned to receive at least one tab upondeformation thereof.
 11. The system of claim 10, further comprising atleast one slit formed in the outer surface of the tube proximate the atleast one tab, the at least one slit allowing the at least one tab todeform in a longitudinal direction.
 12. A bone tunnel buttress system,comprising: a bioimplantable elongate hollow tube having an outersurface and opposed proximal and distal ends, the hollow tube havingbone ingrowth pores formed on the outer surface thereof; and at leastone external securing member formed on the outer surface of the tube,the bone tunnel buttress being effective for deployment within a bonetunnel such that the external securing member in cooperation with theouter surface pores, secures the buttress against removal from the bonetunnel; wherein the bone tunnel buttress is constructed from anabsorbable material.
 13. The system of claim 12, wherein the absorbablematerial is polydioxanone.
 14. A bone tunnel buttress system,comprising: a bioimplantable elongate hollow tube having an outersurface and opposed proximal and distal ends, the hollow tube havingbone ingrowth pores formed on the outer surface thereof; and at leastone external securing member formed on the outer surface of the tube,the bone tunnel buttress being effective for deployment within a bonetunnel such that the external securing member in cooperation with theouter surface pores, secures the buttress against removal from the bonetunnel; wherein the tube includes a tapered inner lumen extending from aproximal to a distal end of the tube.
 15. A bone tunnel buttress system,comprising: a bioimplantable elongate hollow tube having an outersurface and opposed proximal and distal ends, the hollow tube havingbone ingrowth pores formed on the outer surface thereof; at least oneexternal securing member formed on the outer surface of the tube, thebone tunnel buttress being effective for deployment within a bone tunnelsuch that the external securing member in cooperation with the outersurface pores, secures the buttress against removal from the bonetunnel, and at least one resilient flange located on the outer surfaceof the bone tunnel buttress, the flange positioned on the proximal endproximate the at least one external securing member.
 16. A bone tunnelbuttress system, comprising: a bioimplantable elongate hollow tubehaving an outer surface and opposed proximal and distal ends, the hollowtube having bone ingrowth pores formed on the outer surface thereof; atleast one external securing member formed on the outer surface of thetube, the bone tunnel buttress being effective for deployment within abone tunnel such that the external securing member in cooperation withthe outer surface pores, secures the buttress against removal from thebone tunnel; and a suture retriever, wherein the bone tunnel buttress isadapted to be removably and replaceably disposed on the sutureretriever, the external securing member of the bone tunnel buttressbeing effective to allow the bone tunnel buttress to slide into a bonetunnel in a first direction when urged into the bone tunnel by thesuture retriever while preventing the bone tunnel buttress from slidingout of the bone tunnel in a second direction that is substantiallyopposed to the first direction upon removal of the suture retriever fromthe bone tunnel.
 17. The system of claim 16, wherein the tube isdimensioned to extend substantially through the bone tunnel.
 18. Thesystem of claim 16, further comprising a circular bone rasp.
 19. Thesystem of claim 18, wherein the bone rasp has a cross section similar inshape to a cross section of the bioimplantable elongate hollow tube.